In many contexts, it is useful to automatically recognize or classify physical objects as being instances of particular classes or types of objects. Such automated systems can be used to automate sorting activities that would otherwise require a human to manually view the objects being sorted and to manipulate the objects to perform the sorting process (e.g., directing the object to a particular location by touching the object or by controlling a machine to do so).
One example of an application is in a factory that has a conveyor system, such as conveyor belts, for moving objects through the various stages of the manufacturing process, including assembly, distribution, and delivery processes. At any of the stages of the plant, many different types of objects may arrive, possibly from different production lines, and may therefore be different models of similar products, completely different products, incomplete portions or modules of objects, and the like. The objects may have different characteristics such as size and color. In many cases, the objects may be unsorted, where an object of one type (or class) may be followed by an object of a different type (or different class). As the objects arrive, each object may need to be correctly identified and characterized for subsequent handling. For example, objects may need to be placed inside a suitably sized box, matched with other similar objects (e.g., the left and the right shoe in a pair). As another example, each object arriving on the belt may need to be analyzed for quality assessment, with the goal to identify objects that do not satisfy specific requirements.
As another example, in the context of electronic commerce, an individual customer order may include many disparate items to be packaged into a single box. These items may arrive at a packaging center in random order and may be intermingled with items from other customers' orders. In such environments, it may be necessary to selectively place particular items into different boxes for each order in accordance with the particular list of items (e.g., a packing list).